Pitman construction



J. H. OKELL.

PITMAN CONSTRUCTION. APPLICATION F |LED MAR,20.1920

Patented. NOV.1, 1921.

. INVENTOR 7 ATTORNEY AMES 11.. o nrm, or ztos ANG-ELES, CALIFORNIA, AssreNon T0 OKELL WELL I ncrrmnav COMPA A coranrnnnsnrr, CONSISTING'OF-GORA M. LANE ANDGEORGE E. OKELL, or Los ANGELES, CALIFORNIA.

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To all whom it may concern: if

Be'it known that}I,JA1uns citizen ofthe UnitedStates, reslding' at Los Angeles, in the county of Los 'Angelesand State of California,'have invented new and useful Improvements in Pitman Construo' and metallic cable to which a well drilling tool is attached, whereby said tool may be alternately raised and lowered in an oil well during a drilling operation.

In the drilling and boring of oil wells it is desirable that the tool be lifted and lowered alternately during the drilling operation, and in order to accomplish this actlon the tool is suspended in the well at the end of a cable. The other end of the cable is secured to a suitable hoisting drum which is held stationary at this time. The cable passes over a sheave mounted on the upper end of a pitman which is suitably guided in a derrick disposed adjacent the top of the well, and the lower end of the pitman is pivoted to a crank which is driven by any suitable source of power. Ofttimes the tool becomes clogged and stuck in. the well and during the lifting movement a great strain is placed upon both the cable and the derrick, very frequently to the detriment of both. This is particularly true when a metallic cable is used as there is a minimum amount of yield or stretch to such a cable; as compared with a cable of Manila rope.

The object of my present invention is to provide a pitman construction which wlll overcome the above recited disadvantages.

and will yield upon its upward stroke, thereby relieving the cable of undue strain when the tool to which it is secured becomes stuck or jammed in the well.

Other objects will appear in the following description, will be pointed out in the claim and will be embodied in the accompanying drawings, in which:

Figure 1 is a front elevation of a derrick showing my improved pitman applied thereto.

Fig. 2 is a vertical section of the same, taken on the line 22 of Fig. 1.

Fig. 3 is an enlarged fragmental section Specification of Letters Patent.

H. OKELL, a

Patented Nov. 1, 1921.

Application filed March 20, 1920. 7 Serial No. 367,329.

of the yielding mechanism, showing means appli d thereto for making said yielding mechanism inoperative when it is so desired. Fig. 4 is a transverse section of the same taken on theline 44 of Fig. 3.

Referring to the accompanying drawings, 5 and 6 represent suitable timbers arranged adjacent the head of an oil well upon which is mounted a derrick 7 which comprises "the uprights 8 and 9 tied together by suitable cross bars 10. Journaled in bearings 11 and 12 on uprights 8 and 9 isa drive shaft 13*provide d with the crank 14 disposed between said uprights. Mounted on the crank 14 is an upwardly extending pitman rod 15 provided at its top with a fitting 16, and adapted to extend on either side of fitting 16 is a yoke member 17 The fitting 16 and yoke member 17 are both provided with suitable registering perforations through which passes a pin 18 thereby hinging said members together. The ends of pin 18 extend outwardly on both sides of yoke member 17 and are adapted to be guided in the vertical straps 20 and 21 secured respectively to uprights 8 and 9.

The yoke member 17 has secured thereto an upstanding rod 22 adapted to slide in an upright pipe 23, the upper end of said pipe being provided with a yoke member 24, between the arms of which is mounted a cable sheave 25 by means of a horizontally disposed shaft 26. The ends of shaft 26 are suitably guided between the upright members 8 and 9 and strap members 27 and 28 secured thereto. A washer 30 is adapted to surround upstanding rod 22 and rest upon yoke member 17 and a flange collar 31 is threaded onto the lower end of upright pipe 23. The members 30 and 31 are spaced suitably apart, as shown in Fig. 1 and interposed therebetween are the compression springs 32, which surround upstanding rod 22.

Mounted in bearings 34 secured to timbers 5 and 6 is the usual cable drum 35 around which is wound a cable 36 which passes over sheave 25 and the free end of which is adapted to project downwardly into an oil well to support and operate the desired tool.

In the operation of the derrick apparatus it will be apparent that when power is applied to shaft 13, the crank 14 will operate to reciprocate pitman 15 and 23, thereby the cable 36, but in order to compensate for this strain and to give yielding action to the same, the spring members 32 are provided.

7 Y this construction it is obvious that h theatool becomes stuck, that spring mem bers 32 will become compressed thereby relieving the cable of undue strain and consequently greatly prolonging the life of the same. This is especially true where a metallic cable is used, as such a cable does not have the yielding qualities of a cable made of Manila rope or the like. 7

In the use of the pitman construction under some conditions it is unnecessary to provide the yielding movement so inorder that the pitman movement may be rendered positive on these occasions, I provide the following device which comprises a palr of semi-circular sleeve members 40 and 41' adapted to surround the springgmembers 32 and to be interposed between washer and collar 31, as clearly shown in Fig. 3; and in order that the sleeve members 40 and 41 may be held in proper relation I provide the band 42 which is adaptedto surround said members and to be clamped together'by means of a bolt 43. 7

l/Vhat I claim is:

A pitman comprising a pair of slidably mounted telescoping lineal members, a compression spring interposed between said members, and a spacing member adapted to be inserted between said lineal members, whereby said spring may be rendered inoperative. V

In witness that I claim the foregoing I have hereunto subscribedv my name this 21st day of February, 1920.

JAMES H. OKELL. 

